For the tables I would just use a spreadsheet app like Libre Office Calc, then use some screengrab app you have on your computer to take a screenshot. Stretch the window fullscreen and zoom in to get the biggest screenshot, for printing quality.

But yes definitely Inkscape for the illustrations, that's what it's for .

You can use GIMP to create the same drawings but I think it would take much more time, and if you're inexperienced with graphics app that use layers it would take a really long while to learn. Inkscape on the other hand manipulates objects, which is much more intuitive, and is much easier to use.

The advantage of using SVG (Inkscape) is that it can be rendered to different resolutions. Converting images to pixels can be delayed to the last minute where the resolution of the device can be used. They can be shown at the maximum resolution of the device. This eliminates the blocky or pixelated look of the images.